Population Dynamics and Exploitation of Shoal Bass in the Lower Flint River, Georgia

One of the largest native populations of shoal bass Micropterus cataractae is found in the Flint River and for the most part, remains relatively unstudied.  We defined population characteristics for shoal bass in the lower Flint River, Georgia during 2009–2011.  Electrofishing catch rates for shoal bass averaged 12.7 fish per hour over the study.  Weight–length relationship is described as -5.56 * TL^(3.27).  Fish (N=187) were sacrificed for age and growth analysis.  Ages of sampled fish ranged from age 1 to age 11.  Model parameters (von Bertalanffy) were defined as 564 mm (L_¥ ), 0.312 (K), and –0.089 (t₀).  Male and female growth rates were similar, with average fish requiring 2.35 years to reach 305 mm and 5.11 years to reach 457 mm.  Growth of shoal bass was faster than that of largemouth bass Micropterus salmoides in the Flint River and in Lake Blackshear.  Annual total mortality averaged 44% and ranged from 42–47% annually.  Seven hundred and forty shoal bass were tagged with internal anchor tags to evaluate exploitation.  When adjusted for tag non-reporting, we estimated the percentage of legal-sized shoal bass harvested to average between 8.4–10.4% and ranged from 3.4–20.8%.  With current population dynamics and exploitation levels, an increase in the minimum length limit would likely not increase yield to the recreational fishery.